Effect Of Carbon Dioxide And Salinity Stress On Cucumber Growth

In recent years,the area of protect fields increasingly expands in China,and people attach more and more importance to research of carbon dioxide fertilization,whose effects have been confirmed by many experiments.However ,people have done few studies on the relationship of carbon dioxide fertilization and salinity.The experiment adopts cucumber as treated crop and studies the effets of carbon dioxide, sodium chlorideand calcium nitrate on the physiological indexes,ion absorb and dry weight of cumumber,by the way of water incubation ,combined with indoor analysis.Its aim is to search the reaction of carbon dioxide,sodium chloride and calcium nitrate,so that we hope to find a feasible approach to resolve secondary salinity soil in greenhouse.In the experiment ,the concentration of carbon dioxide is:360,720,1080,1440 μ L/L,that of sodium chloride is 0 and 40mM, that of calcium nitrate is 0,5,10,15mM We adopt the classic methods to determine physiological indexes,and traditional methods to determine the content of ions. The study results have proved:The content of chlorophyl in cumumber leaves decreases in carbon dioxide 720 μ L/L,and increases in carbon dioxide 1080 μ L/L and 1440 μ L/L.The content of proline in cumumber leaves increases in carbon dioxide 720 μ L/L,and decreases in carbon dioxide 1080 μ L/L and 1440 μ L/L.The high concentrations of carbon dioxide in the experiment reduce the content of MDA and SOD in cumumber leaves.40mM sodium chloride decreases the content of chlorophyl,and increases that of MDA,and has no effects on proline and SOD in cumumber leaves.The high concentrations of carbon dioxide in the experiment enhances the total N in all parts of cumumber . Carbon dioxide 720 μ L/L and 1080 μ L/L increase the total P in the root of cumumber,and carbon dioxide 1440 μ L/L reduces it in root of cumumber. The high concentrations of carbon dioxide in the experiment have no effects on the stems and leaves of cumumber.The Potassium ion increases in carbon dioxide 720 μ L/L in all parts of cumumber,and decreases in 1080 μ L/L and 1440 μ L/L in that.The highconcentrationsof carbon dioxide in the expriment decrease the calcium ion and increase the sodium ion in all parts of cumumber.40mM sodium chloride decreases the total N,potassium ioncontent ,calcium ionand have no effects on total P in all parts of cumumber .of chlorophyl,and increases that of MDA,and has no effects on proline and SOD in cumumber leaves.The carbon dioxide treats enhance the dry weight of cumumber,calcium nitrate and sodium chloride treats reduce that respectively.We can find that carbon dioxide treats in the experiment can enhance the endurance to salinity,so that the yield can be increased.